Return bend or header construction for tubular stills or boilers or pipe connections



I QWUQWO OZ fiiayznond 71905066;

R. T. HOWES Filed Jan. 5, 1951 STILLS OR BOILERS OR PIPE CONNECTIONS Dec. 13, 1932.

dtkocmg a Patented Dec. 13, 1932 UNITED STATES PATENT OFFICE RAYMOND THAYER HOWES, 0]? LONG' BEACH, CALIFORNIA, AssIGNoR or'oNE-HALF TO JAMES w. WEIR, or Los ANGELES, CALIFORNIA RETURN BEND OR HEADER CONSTRUCTION FOR TUBULAR STILLS OR BOILERS OR PIPE CONNECTIONS Application filed January 5, 1931. Serial No. 506,630.

This invention relates to the construction of return bends and tube sheets such as are employed in the construction of tubular stills, boilers, heaters, or the like. In such struc- 5 tures, banks of tubes are employed connected at their ends with return bends so as to return a fluid flowing through one tube, into and thru an adjoining tube. These tubes are usually arranged in connected parallel rows,

0 banks or sections within a furnace constructed with a suitable foundation, settings and supports. 1

Constructions of this kind usually necessitate the use of expensive heat-resisting tube 5 supports usually in the form of tube sheets,

bars or rails.

The general object of this invention is to provide a return bend consisting of a number of interchangeable members or parts soconstructed as to overcome many of the difliculties which have arisen heretofore in the construction and operation of tubular stills, heaters, boilers or the like. I Y

7 one object of this invention is to eliminate 5 the use of separate tube sheets or other forms of end supports by so constructing two members of the return bend that an integral part of the same will be in the form of cast blocks of such size and dimensions that they will fit 0 together enabling them to be .laid in lapped joints when connected to the tube ends in proper positionin the furnace to form tube sheet end supports. A particular advantage is that while this member is subjected to the direct heat of the furnace it is cooled to such an extent by the fluid passing thru it that expensive heat resisting metal is not necessary, and warping is prevented by the many flexible oints. I

Another object is to provide means of easily and quickly removing and replacing one or more tubes or parts of the return bend as desired.

Another object of this invention is to provide a return bend so constructed that all fluid passing through the same comes into actual contact with but one relatively light interchangeable member of the whole, thereby making it possible to use a relativelvexpensive non-corrosive alloy for this lighter exposed part of the return bend when necessary to prevent corrosion or erosion and cheaper ordinary material for the heavier parts of the assemblyeach in accordance with its requirements.

Another object of this invention is to provide a flexible and leak proof joint with the return bend at the tube ends making perfect alignment unnecessary.

Another object of this invention is to make the use of gasketsbetween joints unnecessary, at the same time avoiding the necessity for a wedging action between the attached parts.

Further objects of the invention will appear hereinafter.

The invention consists of the novel parts andcombination of parts to be described hereinafter, all of which contribute to produce an efiicient return bendconstruction for tubu lar stills, heaters or boilers.

A preferred embodiment of the invention is described in (the following specification, While the broad scope of the invention is pointed out in the appended claims.

In the drawing:

Fig. 1 is an end elevation showing a partion of the i bers of the return bends form ing a supporting tubesliee't embodying my invention and illustrating a plurality of adjacent blocks laid in lapped joints carrying the endsof the tubes that are connected by the return bends, certain parts being broken aW iY- Fig. 2 is a section taken on the line 2-2 of Fig. 1 and showing a completely assembled return bend and the two adjacent blocks together with their connecting return bend member, the ends of the tubes being represented as broken away,

Fig. 3 is a section taken on the line 3-3 of Fig. 2 and further illustrating the construction.

Referring more particularly to the parts, the members of the return bend which form the'supporting' tube sheet which may be in either a horizontal or a vertical position, is composed of a plurality of members 1 which are preferably of rectangular or block form, arranged in rows in a staggered relablocks are hollowor of skeleton form having a square disc-like body 3 with a stout marginal flange 4 that extends all around the block. The disc portion of each block is provided with a circular opening 5 in which is received a bushing 6, said bushing having an enlarged collar 7 at its inner end that overhangs the edge of the opening 5.

For convenience in assembly, if desired the bushing 6 may be split as indicated by the dotted line at 8. Each tube 9 is formed at its end with an integral enlargedhead or flange 10 on the outer face of which is produced a on form or seat 11 which is preferably of spherical form. .The tube 9 is of somewhat smaller diameter than the opening 12 through the bushing so as to permit lateral play'of the tube with respect to the'bushing. Adjacent tubes in the same row are connected two by two by a return bend 13. This bend is preferably a casting and is formed at its ends with seat faces 14 of sphericalform to correspond with the form of the cup-form seats 11. These faces 14 and 11 are intended to cooperate together to form a ground joint. The blocks are provided with means for clamping the return bends securely on the seats 14. Any suitable means'may be provided for this purpose but I prefer to provide each block with two oppositely disposed outwardly extending arms 15 which are formed integral with the block and may be considered as reduced extensions of the flange 4. Near their outer ends these arms are provided with aligned slots 16 which receive the ends of a stout cross-bar 17. This-cross-bar carries a clamping screw 18, the tip of which engages a seat 19 formed on the bend in axial alignment with the corresponding tube.

With this construction, it will be evident that by screwing up these clamping screws 18 tightly the return bends 13 can be very securely fastened on the ends of the tubes so as to prevent leakage. When clamped in this way, it will be evident that the flanges or heads 10 of the tubes will be clamped rigidly between the bushings and the seat faces 11 of the bends. By reason of the existence of the slight play of the tube in the bushing, it

' will be evident that the bushing does not interfere in any way with the tube 9 aligning itself exactly with the adjacent end of the return bend; hence a very tight joint can be made between the faces 11 and 14.

The construction illustrated in Figs. 2 and 3 is typical. At the ends of the rows of 1 blocks where connection must be made from a tube in one row, over to a tube in another row, a diagonally placed return bend must be employed which is of special construction. However, as far as the connection between the bend and the tube is concerned,

tance between the centers of the two con-.

nected tubes.

It is understood that the embodiment of v the invention described herein is only one of the man embodiments this invention may take, and do not wish to be limited in the practice of the invention, nor in the claims, to the particular embodiment set forth. 1

At present it iscommon practice to support the tubes of stills of thiskind on'expensive silicon steel bars or frames. My supports, consisting as they doof castings that are integral with the bends themselves, are cooled by the substance passing through them and they have only one face subjected to the heatof the furnace gases.

However, it is to be understood that. the return bend may be used to connect any metal pipe where a return bend is require and when soused the herein described lateral extensions forming the block like ends of the yokes may be omitted.

I claim: 1

1. In a tube sheet construction the com-- bination of a plurality of substantially rectangular blocks arranged in rows with the edges of the blocks substantially touching each other, each of said blocks having an opening therein with a bushing, a tube of considerably smaller diameter than the opening, received in each bushing so that each tube is capable of lateral movemenhwithin its bushing, each tube having a shoulder seating on the bushing, and having an integral seat on its end, return bends connecting the tubes in pairs with the ends of the return bends seating, against the said integral seats on the ends of the tubes and forming a joint therewith, and means for clamping the return bends against the ends of the tubes,

the openings in said bushings permitting lateral shifting of the tubes so that the tubes center themselves respectively on the;

osition ends of the return bends, and the of the tubes is determined by the en s of the bends.

2. In a tube sheet construction, the com bination of a plurality of f'substantiall rectangular blocks arrangedin rows wit the edges of the blocks substantially touching each other, each of said blocks having an opening therein with a slit bushing, a

tube of considerably smaller diameter than the opening, received in each bushing so that each tube is capable of lateral movement within its bushing, each tube having a shoulder seating on the bushing, each tube having a cup-form seat at its end, return bends connecting the tubes in pairs and having tapered ends received on the cup-shaped seats and cooperating with the same to form joints, and means for clamping the return bends against the ends of the tubes, the openings in said bushings permitting lateral shifting of the tubes so that the tubes center themselves respectively on the ends of the return bends, and the position of the tubes is determined by the ends of the bends.

3. In a tube sheet construction, the combination of a plurality of substantially rectangular blocks arranged in rows with the edges of the blocks substantially touching each other, each of said blocks having an opening therein with a split bushing, a tube of considerably smaller diameter than the opening, received in each bushing so that each tube is capable of lateral movement within its bushing. each tube ha'vi-n'ga'shoulder seating on the bushing, each tube having a cup-form seat at its end, return bends connecting the tubes in pairs and having tapered ends received on the cup-shaped seats and cooperating with the same to form joints, and means for clamping the return bends against the ends of the tubes, said clamplng means including a cross-bar corresponding to each tube, with its ends supported on its corresponding block, and a clamping screw carried in the bar and seating on the outer side of the return bend.

4. In a tube sheet construction, the com bination of a plurality of substantiall rectangular blocks arranged in rows, each of said blocks having an opening therein with a split bushing, a tube of considerably smaller diameter than the opening, received in each bushing so that it is capable of lateral movement in the bushing, each tube having a shoulder seating on the bushingand covering the opening in the bushing, each tube also having a cup-form seat at its end, return bends connecting the tubes in pairs and having tapered ends received on the cup shaped seats and cooperating with the same to form joints, and means for clamping the return bends against the ends of the tubes, the openings in said bushings permitting lateral shifting of the tubes so that the tubes center themselves respectively on the ends of the return bends, and the position of the tubes is determined by the ends of the bends.

Signed at Long Beach, Calif., this 9th day of December, 1930.

RAYMOND THAYER HOWES. 

